Synchronized control gear for machine guns



Sept. 21, 1937.

J. L. HATCHER SYNCHRONIZED CONTROL GEAR FOR MACHINE GUNS Filed Aug. 21, 1936 In vanvur' James LJ'IatEh E1" Attorney UNITED STATES PATENT OFFICE REISYNCHRONIZED CONTROL GEAR FOR MA- KJHINE GUNS llames L. Hatcher, United States Army, Winthester, Va.

lipplication August 121, 1936, Serial No. 97,135

Claims. (Cl. 892'7) tGranted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be manuactuate a cam follower In which is perpendicular factured and used by or for the Government for to the shaft 5. The cam follower is normally governmental purposes, without the payment to held in engagement with the cam member by a me of any royalty thereon. lever H which is squared on a shaft l2 and which r This invention relates to a synchronized conis secured to an impulse cable l3 leading to the trol gear for machine guns. trigger motor which is only diagrammatically In arranging a machine gun to fire between the shown and indicated a A Sp 95 act propeller blades of aircraft it is customary to conon the cable 13 causes the lever l l to exert a prestrol the operation of a trigger motor on the gun sure of about 100 pounds on lFhe Cam follower. by means of an impulse generator associated with A plate l6 fixed on the sleeve 1 Parallel to the 10 the engine that drives the propeller. .An impulse 0am member 9 s Provided 011 s pp es t i i member in t form of a cam with an upper control cam l1 and a lower control lower is normally held in inoperative position by cam The control s py t s m r la control plunger which is withdrawn when the ative position on the plate and eXtend l n the 15 cam follower is to function in firing the gun, margin the eof o a out 180 e The p The purpose of this invention is to provide a of the pp m I? fo lows t Of the impulse positive mechanism for moving the control cam 9 when the shaft 5 is rotating i the P p plunger into and out of locking engagement with direction and the purpose of this arrangement the cam follower. will presently appear while the peak of the lower 20 To these and other ends, the invention consists cam I8 is coextensive with the peak of the imin the construction, arrangement and combinapulse cam 9. The trailing end of the upper cam tion of elements described hereinafter and I1 gradually recedes from the periphery of the pointed out in the claims forming a part of this plate 16 so that its outer side forms a cam surspecification. face [9 which will hereafter be referred to as the 25 A practical embodiment of the invention is safety cam.

illustrated in the accompanying drawing, where- A reciprocally mounted plunger 20 arranged in parallel to the shaft 5 and extending past the Fig. 1 is a more or less diagrammatic view plate 16 has a tapered upper end 2| adapted to partly in side elevation and partly in section enter a recess 22 in the cam follower Ill for the showing the control gear at the instant when purpose of holding the follower out of the path of the plunger is completely seated in the recess of movement of the cam member 9. The plunger is the cam follower; provided with a pair of apertures 23 and. 24 for Fig. 2 is a similar view showing the position of respectively receiving an upper arm 25 and a the parts preparatory to moving the plunger into lower arm 26, the arms being pivotally mounted engagement with the cam follower; on the ends of a centrally pivoted lever 21.

Fig. 3 is a view showing the plunger held out Upon movement of the lever 21 the arms 25 and of engagement with the cam follower. 26 are displaced so that their free ends are selec- Fig. 4 is a plan view of the cam shaft. tively positioned in the path of movement of the Figs. 5 and 6 are detail views in side and end control cams l1 and IS. A spring 28 acts on the 40 elevation of the latch. upper part of the lever 21 to normally maintain Referring to the drawing by characters of refthe upper arm 25 in engagement with the upper erence there is shown the impulse generator of a ontr l cam H. The lower arm 26 engages the gun control assembly including a S f 15 having lower control cam l8 only when forced into that 4.5 a gear 6 on its w e whereby it is driven position by the gun operator when the latter is from the aircraft engine. Asleeve I mounted on acting on a trigger, the actuating force being a reduced part of the shaft 6 is connected thereto applied r transmitted either mechanically or in a y u t manner. p fi a y y m ans f a electrically as is well understood in the art. split wedge nut B threaded on the other end of The upper end of the lever 21 carries a finger the shaft. 29 adapted to enter a notch 30 in the plunger 20 An impulse cam member 9 is fixed on the upper when the plunger is in engagement with the cam end of the sleeve, being integral therewith or follower as shown in Fig. 1. The movement of the formed separately therefrom when necessary for finger is limited by means of a stop pin 3| riding the purpose of assembly. The cam member is in a slot 32 in the lever (Fig. 5) and is normally about 55 degrees in width and is arranged to moved towards the notch by a spring 33. 0

The parts are normally in the position shown in its pivot. In this position the arm 25 cannot Fig. 1, the plunger 20 being engaged in the recess move the plunger towards the follower. 22 of the cam follower l so that the gun cannot I claim: be fired and the impulse cam member 9 rotates 1. In a synchronizing gear for machine guns, with the shaft without acting on the cam folan impulse generator including a driven shaft, a 5 lower. The pressure of the spring [5 tending to cam member on said shaft, a cam follower having move the cam follower is sufiiciently great to a recess, means for normally holding the follower prevent removal of the plunger from the recess against the cam member, a reciprocally mounted 22. However as an additional safeguard the plunger adapted to enter the recess of the followfinger 29 is engaged in the notch 30 of the er to hold it away from the cam member, said 16 plunger to prevent its withdrawal. plunger having a pair of spaced apertures, a plate When the gun is to be fired the operator moves on the driven shaft, a pair of control cams posithe lever 21 to place the free end of the lower tioned marginally on opposite sides of the plate,

The cam l8 rocks the arm about its pivot and the having one end receding from the periphery of 5 mediately moved by the spring l5 into engageinto the path of the control cams to be rocked 20 ved away from the shaft 5 against ment adapted to be rendered inoperative by the the action of the spring I5 and as soon as the safety cam when the driven shaft is rotated in the 25 cam member passes the follower, the latter is wrong direction. moved towards the shaft 5 by the spring l5. This 2. In a synchronizing gear for machine guns, reciprocation of the cam follower produces operaan impulse generator including a driven shaft, a tion of the trigger motor and causes firing of the cam member on sald shaft, a cam follower having gun as is well understood in the art. a recess, means for normally holding the follower When the cam member 9 has moved the folagainst the cam member, a reciprocally mounted lower away from the shaft the recess 22 in the plunger adapted to enter the recess of the followcontrol cam l8. It is only necessary to hold the plate, a pivoted lever alongside the plunger, a plunger withdrawn during the time that the pair of arms pivoted to the lever and each eX- recess 22 of the reciprocating follower is in line tending through an aperture of the plunger, said with the plunger. Firing of the gun will conarms adapted when moved into the path of the tinue so long as the lower arm 26 is in position to control cams to be rocked thereby to reciprocate be engaged by the lower control cam l8. the plunger into and out of locking engagement When it is desired to discontinue firing, the with the follower. operator causes removal of the lower arm 26 from 3. In a synchronizing gear for machine guns,

the path of the cam l8 and as a consequence the an impulse generator including a driven shaft, a spring 28 automatically moves the upper arm 25 cam member on said shaft, a cam follower havthe shaft and positions the recess 22 in line with the follower to hold it away from the cam memsition the follower is in the safe or inoperative able with the plunger, said arms adapted when t e y O the p f the recess 22 the an impulse generator including a driven shaft,

gagement With the follower- This is evident and means selectively movable into the path of cause under such a condition the recess 22 would the control cams and t t thereby to move not be in line with the plunger. In the event of the plunger into. d ut; of locking engagement rotation of shaft 5 in the wrong direction, the ith th follower,

safety cam l9 engages the arm 25 and moves it JAMES L. HATCHER. away from the wheel I6, without rocking it about 

